Untreated internal combustion engine emissions (e.g., diesel emissions) include various effluents such as NOx, hydrocarbons, and carbon monoxide, for example.
Moreover, the untreated emissions from certain types of internal combustion engines, such as diesel engines, also include particulate carbon-based matter or “soot.” Federal regulations relating to soot emission standards are becoming more and more rigid thereby furthering the need for devices and/or methods which remove soot from engine emissions.
The amount of soot released by an engine system can be reduced by the use of an emission abatement device such as a filter or trap. Such a filter or trap is periodically regenerated in order to remove the soot therefrom. The filter or trap may be regenerated by use of a fuel-fired burner to burn the soot trapped in the filter. In such a case, the fuel-fired burner generates heat which is transferred to the downstream filter to burn the soot trapped in the filter. Poor temperature distribution of the generated heat can cause some regions of the filter to be hotter than desired, and other regions to be colder than desired. In the regions that are hotter than desired, the filter can potentially be damaged, whereas the colder regions may not be regenerated.